Before any Apple fans get a chance to touch the new iPhone or Apple Watch, investors were already giving the world's most valuable company their seal of approval for its latest product unveilings.

Over the course of an event Tuesday that introduced bigger-screen iPhone 6 and iPhone 6 Plus and Apple's first wearable -- the Apple Watch -- shares rose as high as $103.08, a 4.8 percent increase from the previous day's closing price. They nudged about a percentage point higher during the introduction of the Apple Watch, and were holding steady at $100.63, or 2.3 percent higher, as the event approached its close -- about the same level they were trading at as the presentation began.

Shares ended up closing the day down less than a percentage point at $97.99.

Apple, which nearly declared bankruptcy before Steve Jobs returned to the helm in 1997, now is the most valuable company in the US. Its market capitalization of more than $590 billion tops Exxon Mobil, Microsoft, and IBM, all giants in their own right. In Apple's last fiscal year, ended September 28, 2013, the company generated $170.91 billion in sales and $37.04 billion in profits.

Apple shares have been hitting records for the past few weeks, most recently setting an all-time high of $103.74 on September 2. But shares dropped more than 4 percent the following day as worries rose about the security of Apple's devices and after rival Samsung introduced its newest phablets, the Note 4 and Note Edge.

Apple shares had slid from their earlier high in 2012 on worries that Apple CEO Tim Cook wouldn't be as successful as co-founder Steve Job at developing new blockbuster devices. Cook has promised several times over the past year that Apple would enter in 2014. And in May, Eddy Cue, head of iTunes and the man behind Apple's $3 billion acquisition of headphone and streaming service Beats, upped the pressure by boasting that the consumer electronics giant is working on its " best product pipeline in 25 years."

Along with boasting about new devices, Apple also has taken steps to return more cash to shareholders. The company in April said it planned to give investors six additional shares of stock for every Apple share they owned as of June 2. Because of the split, shares now trade at a much lower level than in the past, but it also makes the stock more accessible to investors. It's much cheaper to own a chunk of Apple at about $100 versus $600. The split went into effect in June, with shares trading at about $93.

The stock split came as part of Apple's effort to meet the demands of current shareholders, as well as attract a new group of investors. Under the leadership of Cook, Apple started returning some of its massive cash hoard to investors. Shareholders, such as activist Carl Icahn, asked for even more, and Apple earlier this year revealed a big increase to its dividend and share repurchase program, along with the stock split. The company at that time boosted the amount of cash that it's returning to shareholders by about $30 billion to more than $130 billion.